_The Harlot's Progress_ and _The Rake's Progress_ are alike interesting for the parodic ballad opera pattern of setting new words to familiar tunes. Though neither work includes the music, some songs indicate familiar melodies such as "Let us take the road" from _The Beggar's Opera_. In _The Harlot's Progress_, the six "Airs" come from varied sources, with new lyrics by Theophilus Cibber. Of the approximately 24 unnumbered tunes and catches in _The Rake's Progress_, the most outstanding in connection with the print sequence is "Black Joke," Richard Leveridge's bawdy tune shown by Hogarth in the Rose Tavern print being sung by a pregnant woman (Pl. 5). In the stage piece, this song is part of a medley sung to Rakewell by the various professionals who compete for his money. The most important tunes are those from _Poor Vulcan!_ the burletta by Charles Dibdin (February 1778), supporting my 1778-1780 date for _The Rake's Progress_ manuscript. The sources used to trace the musical airs include Claude Simpson's _The British Broadside Ballad and Its Music_ (New Brunswick: Rutgers University Press, 1966); Minnie Sears' _Song Index_ (and _Supplement_) (New York: Wilson Company, 1926 and 1934); Edythe N. Backus: _Catalogue of Music Printed Before 1801_ (San Marino, Cal.: The Huntington Library, 1949), and William Barclay Squire, "An Index of Tunes in the Ballad-Operas," _The Musical Antiquary_, II (October 1910), 1-17.[18] E. V. Roberts points out that "the lack of a ballad designation for a ballad-opera air usually means that the tune in question was composed specially for that ballad opera" and that, because most "unnamed tunes were unknown outside their ballad operas," they were "neither copied nor printed, and simply do not turn up in the collections."[19] The catches in _The Rake's Progress_ are not traceable. The numbering for songs in _The Rake's Progress_ is my own. Airs from both plays give us some idea of the rich musical treasure English stagewriters could draw upon for theatrical offerings in the eighteenth century.[20] THE HARLOT'S PROGRESS _Air I_: "What tho I am a Country Lass" is an eighteenth century ballad by Martin Parker printed in _Orpheus Calendonius; or, A Collection of Scots Songs Set to Music by W[illiam] Thomson_, II (London 1733), p. 85. Its first two lines are "Although I be but a Country Lass/Yet a lofty Mind I bear-a." It was used by Theophilus Cibber (as Air XII) in his 1732 one-act version of Charles Coffey's _The Devil to Pay_ where the transformed cobbler's wife Nell sings: "Tho late I was a Cobler's Wife,/In cottage most obscure-a" (pp. 20-21). In _The Harlot's Progress_, this air, sung by Madame Decoy, is clearly appropriate for seducing Kitty-Moll into the world of bawds and prostitutes, with its theme of magical change and the conquest of innocence by vice.